1. Field of the Invention
The present invention relates to a data processing apparatus, an information processing method, and a program for achieving the information processing method.
2. Description of the Related Art
Conventionally, an information processing system capable of transitioning to a power saving state so as to reduce standby power consumption has been known. As an example of the information processing system like this, there is a system which consists of a controller (main controller) having a main CPU (central processing unit) and a network controller having a sub CPU.
In the power saving state, the system like this stands by in a condition that power supply to each module of the main controller is being stopped while normal power supply to each module of the network controller requiring less power is being maintained. Further, in a case where a predetermined packet is received from a network, the system like this still reduces power consumption by using a so-called substitute response technique in which the network controller responds to the packet reception while stopping the power supply to the main controller.
In the conventional substitute response technique, when the network controller is in the power saving state, the network controller determines whether or not each packet received by the network controller itself coincides with a data pattern of an ARP (Address Resolution Protocol) request packet to the network controller. Further, in the power saving state, the network controller determines whether or not each packet received by the network controller itself coincides with a data pattern of a packet (i.e., a wake-up packet) which should be processed by the main controller after returning the main controller from the power saving state.
Then, when it is determined that the received packet coincides with the data pattern of the ARP request packet, the network controller transmits transmission data stored in a transmission data register to a LAN (local area network) as an ARP response packet (that is, a substitute response is performed). On the other hand, when it is determined that the received packet coincides with the data pattern of the wake-up packet, the network controller returns the main controller from the power saving state by outputting a wake-up signal to the main controller. It should be noted that the substitute response technique like this has been described in Japanese Patent Application Laid-Open No. 2008-301077.
In recent years, applications, operating systems and the like for remotely managing various devices by using management protocols such as an SNMP (Simple Network Management Protocol) and the like tend to increase. For this reason, since there are many possibilities that various devices receive various kinds of packets for each operational environment of a customer's device, it is difficult to anticipate the packet flowing for each operational environment of the customer's device.
As a result, even if a data pattern to be used for a substitute response or a wake-up has been previously registered in a device, a situation of returning the device from a power saving state without performing the substitute response may occur according to a customer's operational environment, by the reason that the substitute response is impossible. Moreover, since unnecessary coincidence between a received packet and a previously registered unnecessary data pattern is drawn according to circumstances, a situation of unnecessarily returning a device from a power saving state may occur.
It is conceivable as one countermeasure to previously register every possible data patterns. However, since parts of devices each including a network controller capable of operating in a power saving state operates on resources of minimized number in terms of power saving, there are limitations to register all the data patterns for each of these devices.
Moreover, it is conceivable as another countermeasure to enable to change the data pattern according to a kind of packet flowing on a network by a user's operation of registering and setting the data pattern through an external interface of the device such as a USB (universal serial bus), a network, a user interface screen or the like. However, in this case, since an operator (a user, an administrator or the like) of the device has to register the data patterns, an operator's workload increases resultingly.